The adsorption of oxygen on NiAl(001) at 300 K and 20 K

R. Franchy*, Shu Kong SO, P. Gaßmann

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

The adsorption of oxygen on NiAl at 300 K and 20 K has been studied by means of high resolution electron energy loss spectroscopy (EELS), low energy electron diffraction (LEED) and Auger electron spectroscopy (AES). The adsorption of oxygen at 300 K leads to formation of a thin film of amorphous aluminum oxide (a-Al2O3). After oxygen adsorption at 300 K and annealing of the oxygen-saturated surface to 1200 K, a well-ordered thin θ-Al2O3 film is formed. After annealing of the oxygen-saturated surface to 1400 K, an α-like Al2O3 oxide is grown. Even at 20 K oxidation of the NiAl(001) surface is found. However, at higher exposure (≥ 5 L) oxygen physisorbs and the EEL spectrum exhibits characteristics of resonance scattering. The resonance energy for physisorbed oxygen on the amorphous Al oxide layers formed at 20 K has a value of 7.0 eV. The frequency of O-O stretching vibration for physisorbed O2 is 193 meV. The line shape of this mode is asymmetric with a pronounced tail on the high energy side. The asymmetric line shape corresponds to multiple losses due to the overlap of the O-O stretching mode with low frequency modes. After physisorption of oxygen at 20 K on the α-like Al oxide layers, the resonance energy is shifted to 9.0 eV, a value close to that of oxygen in the gas phase.

Original languageEnglish
Pages (from-to)1909-1917
Number of pages9
JournalSurface Review and Letters
Volume3
Issue number5-6
DOIs
Publication statusPublished - 1996

Scopus Subject Areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'The adsorption of oxygen on NiAl(001) at 300 K and 20 K'. Together they form a unique fingerprint.

Cite this